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• About memory and delete object in c++

  - by barssala

  I will give some examples and explain. First, I declare some object like CString* param = new CString[100] And when I declare this one, my memory would increase a little bit because it's some implemented string. Then I store this object in some list of CString just like List<CString> myList = new List<CString>; // new list of CString myList.add(param); This is my question: I wanna know, when I delete myList, my param isn't deleted, right? And memory in param still exists. Do I misunderstand?

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• Counter variable for class

  - by George

  I am having problem getting this piece of code to run. The class is Student which has a IdCounter, and it is where the problem seems to be. (at line 8) class Student: def __init__(self): # Each student get their own student ID idCounter = 0 self.gpa = 0 self.record = {} # Each time I create a new student, the idCounter increment idCounter += 1 self.name = 'Student {0}'.format(Student.idCounter) classRoster = [] # List of students for number in range(25): newStudent = Student() classRoster.append(newStudent) print(newStudent.name) I am trying to have this idCounter inside my Student class, so I can have it as part of the student's name (which is really an ID#, for example Student 12345. But I have been getting error. Traceback (most recent call last): File "/Users/yanwchan/Documents/test.py", line 13, in <module> newStudent = Student() File "/Users/yanwchan/Documents/test.py", line 8, in __init__ idCounter += 1 UnboundLocalError: local variable 'idCounter' referenced before assignment I tried to put the idCounter += 1 in before, after, all combination, but I am still getting the referenced before assignment error, can you explain to me what I am doing wrong? Thank you Edit: Provided the full code I have

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• indexing question

  - by user522962

  I have a table w/ 3 columns: name, phone, date. I have 3 indexes: 1 on phone, 1 on date and 1 on phone and date. I have the following statement: SELECT * FROM ( SELECT * FROM people WHERE phone IS NOT NULL ORDER BY date DESC) as t GROUP BY phone Basically, I want to get all unique phone numbers ordered by date. This table has about 2.5 million rows but takes forever to execute....are my indexes right? UPDATE: My EXPLAIN statement comes back with 2 rows: 1 for primary table and 1 for derived table. It says I am using temporary and using filesort for my primary table. For my derived table, it says my possible keys are (phone), and (phone, date) but it is using filesort.

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• Structure within union and bit field

  - by java

  #include <stdio.h> union u { struct st { int i : 4; int j : 4; int k : 4; int l; } st; int i; } u; int main() { u.i = 100; printf("%d, %d, %d", u.i, u.st.i, u.st.l); } I'm trying to figure out the output of program. The first outputs u.i = 100 but I can't understand the output for u.st.i and u.st.l. Please also explain bit fields.

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• Framework for creating mock objects in Java

  - by Amir Rachum

  This is NOT a question about which is the best framework, etc. I have never used a mocking framework and I'm a bit puzzled by the idea. How does it know how to create the mock object? Is it done in runtime or generates a file? How do you know its behavior? And most importantly - what is the work flow of using such a framework (what is the step-by-step for creating a test). Can anyone explain? You can choose whichever framework you like for example, just say what it is.

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• Programming terms - field, member, properties (C#)

  - by Petr

  Hi, I was trying to find meaning of this terms but especially due to language barrier I was not able to understand what they are used for. I assume that "field" is variable (object too?) in the class while "property" is just an object that returns specific value and cannot contain methods etc. By "member" I understand any object that is declared on the class level. But these are just my assumptions based on commented code samples where some careful programmers used "property region" etc. I would really appreciate if someone could explain it to me.

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• Resetting a while loop

  - by Patrick Beardmore

  I have found a confusing thing in a php script I am writing to generate some javascript. Here it is below, slightly simplified. The second while loop won't run unless I comment out the entire first while loop. Can anyone explain why? Many thanks. <?php $listid = 2; //DEMO ONLY $result1 = mysql_query("SELECT words.wid,words.wordmd5,words.word FROM words,instances WHERE words.wid = instances.wid AND instances.lid = \"$listid\""); $result1copy = $result1; $count1 = 1; while( $row = mysql_fetch_object( $result1 ) ) { print "words_left[$count1] = \"".$row->word."\";\n"; //Increment the array counter (starts at 1) $count1++; } ?> //Some javascript <?php $count2 = 1; while( $row = mysql_fetch_object( $result1copy ) ) { print " $count2 then $row->wordmd5 "; $count2++; } ?>

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• Null Pointer Exception with an array of bitsets

  - by p0ny

  could someone explain to me why the following results in a Null pointer Exception? And how to set a value for bitarray[0]? BitSet[] bitarray; bitarray= new BitSet[10]; bitarray[0].set(1); Also, why something like this work and not result in a pointer exception? BitSet[] bitarray = new BitSet[10]; BitSet bits = new BitSet(32); bits.set(1); bitarray[0] = bits; Thanks

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• Linq to Sql GroupJoin Paging oddity

  - by OllyA

  I have noticed a strange Sql Translation in a LinqToSql Query I was trying to optimise. If I execute the following Recipients.GroupJoin( RecipientAttributes, x => x.Recipient_Id, y => y.Recipient_Id, (x,y) => new {Recipient = x, Attributes = y}) .Skip(1) .Take(1000) It executes in a single query as expected. However Recipients.GroupJoin( RecipientAttributes, x => x.Recipient_Id, y => y.Recipient_Id, (x,y) => new {Recipient = x, Attributes = y}) .Skip(0) .Take(1000) executes in a separate query for each Attributes selection. Removing the Skip(0) makes no difference either. Can anyone explain this and is there something I can do to get the first page query executing in a single sql statement?

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• Postfix evaluation in C

  - by Andrewziac

  I’m taking a course in C and we have to make a program for the classic Postfix evaluation problem. Now, I’ve already completed this problem in java, so I know that we have to use a stack to push the numbers into, then pop them when we get an operator, I think I’m fine with all of that stuff. The problem I have been having is scanning the postfix expression in C. In java it was easier because you could use charAt and you could use the parseInt command. However, I’m not aware of any similar commands in C. So could anyone explain a method to read each value from a string in the form: 4 9 * 0 - = Where the equals is the signal of the end of the input. Any help would be greatly appreciated and thank you in advance :)

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• Playing a .wav sound file in JPanel/JFrame using javax (Swing)

  - by JavaIceCream

  I need some code example on how I would use a filepath from a harddrive location to then play a .wav sound file when opened in swing GUI. I don't need it to show a play button, or pause or stop. I just want it to play when I select the 'Sound' option from my 'Files' in my window (I know how to do that already, no need to explain that). So basically, just how to play a .wav sound file from a filepath (i.e. c:/cake/thereisnone.wav) inside of a JFrame. And how can I easily apply methods to that sound file afterwards. Also, if anyone knows how to apply methods on a BufferedImage in a JFrame, that would be helpful too. Thank you very much everyone!

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• oomla.. GoDaddy.. FileZilla ... :S

  - by user282659

  have created a a website in my localhost computer using Joomla Now I want to launch the site into the web.. So I brought a domain from GoDaddy.com .. Im a newbie into this and I was using This Tutorial in order to set up the website... Now Im Stuck in the Step 08 Which asks to upload some files into the web host directory... I used FileZilla as my FTP Client .. When I give the host name and the password, Port number as 21 and try to login it says.. Connection Timed Out.. and says.. Could Not Connect to server . Plase explain m on how to use the FileZilla.. And Solve th above problem ..

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• PHP using count() with array

  - by seb

  Hi there, Im trying to get the amount of elements in an array using the count() function, the result is a bit puzzling to me, considere the following example. Assume that the user ID provided is wrong, and therefore had no matches, wouldnt then the result of the count function be 0? yet it is 1. can you explain to me why? thanks $q = mysql_query("select password from users where user_name = '" . $userID . "'"); $check = mysql_fetch_array($q); $result = count($check); echo "RESULT:" . $result;

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• Is it possible to implement a lightweight database using Blackberry Persistance options?

  - by Tobias

  First I would like to explain why I want to use alternate Blackberry Persistance options rather than a Blackberry database itself, say SQLite. The reason is that the application i'm designing, I want it to be used in all the previous versions of Blackberry rather than just the ones having OS 5.0 or greater. Now, coming back to the actual question, I have got a database that I want to replicate to be used in the Blackberry application. The database has 8 tables and each table has approximately 12 different columns. One of the table has 1000 rows. Now if I was to implement this DB for a Blackberry application , keeping in mind that it will work on all the versions of Blackberry, what would be the best way to implement it?

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• How to decide between a method or event?

  - by Wil

  I read something ages ago I think by Jon Skeet (which I can't find now) saying that in IL, all events get converted to methods... it was before I understood C# and did not understand it all, but if that is (or even if it isn't) the gist of it.... In a purely hypothetical situation, I was wondering if someone could explain or point me to a resource that says when to use an event over a method? Basically, If I want to have a big red/green status picture which is linked to a Bool field, and I wanted to change it based on the value of the bool, should I: a) Have a method called Changepicture which is linked to the field and changes the state of the bool and the picture. b) Have a get/set part to the field and stick an event in the set part. c) Have a get/set part to the field and stick a method in the set part. d) Other?

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• jquery plugin pattern using jquery.data

  - by web_dev

  I have seen this piece of code in jquery plugin patterns and the notes section mention that we could attach the plugin to the DOM element using the jQuery.data function. What I don't understand is how do I make use of this piece of code. Can somebody provide examples of how to use this functionality and explain its significance? $.fn[pluginName] = function (options) { return $Extend(this).each(function () { if (!$.data(this, 'plugin_' + pluginName)) { $.data(this, 'plugin_' + pluginName, new Plugin( this, options )); } }); };

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• sort a list of objects based on runtime property

  - by jijo

  I have an arraylist of VOs. These objects have many properties and corresponding get/set methods. I want to sort this array list based on a property which I'll be getting in runtime. Let me explain in detail. My VO is like this public class Employee { String name; String id; private String getName() { return name; } private String getId() { return id; } } I will be getting a string ‘sort’ in runtime, which can be either ‘id’ of ‘name’. I want to sort the list based on the value of the string. I have tried to use comparator and reflection together, but no luck. I don’t want to use an if loop and create new comparator classes. Any other thoughts?

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• Replacing Text in a Toggled Anchor with JQuery

  - by willmcneilly

  Hi I'm trying to change the text in an anchor on toggle. I'm doing this way at the moment but have found that once the anchor markup has replaced the toggle no longer works. Can someone please explain why this is happening and a solution? Many thanks. $('a#toggleHeader').toggle(function() { $('#header-wrapper').slideUp(); $(this).replaceWith('< href=\"#\" id="toggleHeader">Show Header</>'); //Note:I've move the anchor because I can only post one anchor as a new user },function(){ $('#header-wrapper').slideDown(); $(this).replaceWith('<a href=\"#\" id="toggleHeader">Hide Header</a>'); });

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• A company that had a successful product but went bust for not innovating?

  - by Dan

  At the company that I work we have a successful software product that did well but is now obsolete and unmaintainable. I am trying to explain that you need to innovate and replace this product with new offering in order to survive. I am looking for some good examples of companies that made the mistake that we are close to making - relying on one successful product way over it's normal lifetime, so I could use it as illustration when making an argument. These products need not be software, emblematic cases that illustrate well this situation but where product was not software are also appreciated.

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• Blackberry browser problem

  - by nhd

  Hi all, I have one site to test, when I run it with my BrowserFieldDemo (in JDE sample)m just display text site, but with the same link, run on Blackberry native browser, it displays properly, and have Zoom in function to zoom. I think the problem here is the size of my site, it's too large. I've tried some different sites and see that the result is same on two browsers, but with this test site, it's unexpected result. Anyone can suggest some solutions for me to fix it? Or explain for me how Blackberry browser can know to resize web page automatically (when it loads the large web page). Thank for any help,

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• ontouch - Switching positions of two views(images) in Android

  - by idish

  I've been looking for that 2 days long and haven't found anything related to it. I'll give an example for my goal. Let's say I have 2 images positioned side by side horizontally. I want the user to be able to switch their positions onlongtouch listener. so let's say that the first image was on the left and the second was on the right side, after switching positions between them, the first image would be in the right and the second would be on the left side. Basically, it is just like in the launcher where you can switch apps positions. Please, if anything is not clear for you, I would like to know, and I'll try to explain it better, thank you.

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• Skeleton framework spacing

  - by user1745014

  I tried to ask this question late lastnight but I was so sleepy i typed the question completely wrong. I'm looking to float my navigation to the right of its current position around 200px more, there is room but it wont move over. You can view the live code here - www.xronn.co.uk/hosting and here is an image to explain my issue a little more http://i.stack.imgur.com/JtL0C.png purple lines the 960px width of the site blue line shows the space free for the navigation to go and the red arrows of course shows which direction i want the navigation to go in (the right) Anyone got any clue why when I push to more to the right, the list starts to sit under each other

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• Drawing lines between windows just like in Interface Builder

  - by Koning Baard

  I have two windows, each with a round NSView: ------------------ ------------ |X-+ Oscillator | |X-+ Mixer | |----------------| |----------| | | | | | O | | O | | | | | | | | | ------------------ ------------ Both windows are in a seperate NIB. I want to be able to draw a line between the two round NSViews at runtime, using drag'n'drop, just like connecting IBOutlets in Interface Builder: ------------------ ------------ |X-+ Oscillator | |X-+ Mixer | |----------------| |----------| | | | | | O-------+-----+-----O | | | | | | | | | ------------------ ------------ I also want to be able to determine to which NSViews the NSViews are connected using the drawn lines. I need this to connect Oscillators to Mixers. I also want to be able to remove the connections by dragging into empty space. Can anyone explain me how to do this? Thanks.

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• Strange postgresql behavior

  - by Sergey

  Hi can someone explain me why it works like this? = select client_id from clients_to_delete; ERROR: column "client_id" does not exist at character 8 but, when putting this inside an IN()... = select * from orders where client_id in(select client_id from clients_to_delete); it works! and select all rows in the orders table. Same when running delete/update. Why it doesn't produce an error like before? Thank you!

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• base pointer to derived class

  - by Jay

  Suppose there are Base class and Derived class. Base *A = new Base; Here A is a pointer point to Base class, and new constructs one that A points to. I also saw Base *B = new Derived; How to explain this? B is a pointer to Base Class, and a Derived class constructed and pointed by B? If there is a function derived from Base class, say, Virtual void f(), and it's been overridden in Derived class, then B->f() will invoke which version of the function? version in Base class, or version that overridden in Derived Class. What if there is a new function void g()in Derived, is B->g() going to invoke this function properly? One more is, is int *a = new double; or int *a = new int; legal?

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